2,3-<9-Isopropylidene-D-glyceraldehyd

SCHEME 38. Nitroaldol reaction of methyl nitroacetate with hexodialdo-l,5-pyranose 200 and 2,3-0-isopropylidene-D-glyceraldehyde (202) catalyzed by silica gel. 

I, 5-pyranose and 2, 3-0-isopropylidene-D-glyceraldehyde. Crystal structure of methyl 7-acetamido-7-deoxy-1,2 3,4-di-O-isopropylidene-L-t/ireoa-D-ga Zacto-octopyranuronate, Carbohydr. Res., 271 (1995) 79-99. 

Reaction of D-glucono-1,4-lactone with 2,2-dimethoxypropane-tin(II) chloride yields the 5,6-0-isopropylidene derivative 13, which on periodate oxidation afforded 2,3-0-isopropylidene-D-glyceraldehyde (21). However, the acid-catalyzed isopropylidenation of D-glucono-1,5-lactone with 2,2-dimethoxypropane afforded methyl 3,4 5,6-di-0-isopropylidene-D-gluco-nate (14) as the main product (22). Reduction of the ester function gave... 

S)-(5-0-tert-Butyldimethylsiloxymethyl)furan-2(5H)-one (Note 1). An oven-dried, 500-mL, round-bottomed flask is charged with 35.5 g (0.27 mol) of 2,3-0-isopropylidene-D-glyceraldehyde (Note 2) and 250 mL of methanol. The flask is cooled in an ice bath during the portionwise addition of 96 g (0.28 mol) of methyl... 

In the presence of water, 2,3-O-isopropylidene-D-glyceraldehyde forms the highly water soluble hydrate 1. Failure to dry the reaction and reslurry the filter cake results in loss of about 10% yield. 

Stereocontrolled addition of 2-furyl anion to 2,3-0-isopropylidene-D-glyceraldehyde can be achieved by the addition of some metal salts. 

Starting from the chiral oxazolone 632 derived from l,2-(9-isopropylidene-D-glyceraldehyde, diastereoselective cyclopropanation has been reported to occur with dimethyloxosulfonium methylide or (diethylamino)phenyloxosulfonium... 

The reaction of alkyl dihalogenoacetate magnesium enolates with 2,3-isopropylidene-D-glyceraldehyde affords the expected /3-hydroxy-a-dihalogenoesters . The erythro isomer is obtained with isopropyl dichloroacetate magnesium enolate. This result is in agreement with theoretical models. 2-Deoxy-pentono-1,4-lactones are obtained after removal of the halogen atom by either Raney nickel or tributyltin hydride reduction (equation 89). 

A higher-branched sugar, 35, was synthesized from 262, obtained by the Grignard reaction of 2,3-O-isopropylidene-D-glyceraldehyde by conversion of the methylene derivative 263 into 264 with osmium... 

A. Dondoni, J. Orduna, and P. Merino, Construction of all 0-alkoxy D-tetrose and D-pentose stereoisomers from 2,3-0-isopropylidene-D-glyceraldehyde using 2-(trimethylsilyl)thiazole as a formyl anion equivalent. Synthesis p. 201 (1992). 

Another method for the preparation of 2-desoxy-D-ribose, using 2,3-isopropylidene-D-glyceraldehyde as an initial material has been outlined briefly by Overend and Stacey.106 The glyceraldehyde derivative was condensed with acetaldehyde in the presence of anhydrous potassium... 

For both of these syntheses 2,3-isopropylidene-D-glyceraldehyde is readily accessible as an initial material since it can be prepared by oxidation of l,2 5,6-diisopropylidene-D-mannitol with lead tetraacetate in solution in dry benzene.188... 

These reactions convert 2,3-O-isopropylidene-D-glyceraldehyde (1) into 2,3-diacetyl-D-erythronolactone (3). 

Reaction of aldehydes with carbon tetrabromide and tin(II) fluoride gives adducts, formed by addition of the elements of bromoform across the carbonyl group, which may be hydrolyzed to acids. In this way, 2,3-0-isopropylidene-D-glyceraldehyde (19) was converted into a mixture of D-erythro (20) and D-//zreo-tetronolactones (21).40... 

The epimeric diketones 281 have been synthesized by condensing 2,3-0-isopropylidene-D-glyceraldehyde with propyne via a Grignard reaction, followed by oxidation of the O-acetylated epimers to the diketones using a ruthenium catalyst and iodosylbenzene as the oxidant.498... 

F. L. Tejero, T. Ready access to enantiopure 5-substituted 3-pyrrolin-2-ones from N-benzyl-2,3-O-isopropylidene-D-glyceraldehyde nitrone. Tetrahedron Asymmetry 1998, 9,1759— 1769. 

When azomethine ylides are generated by condensation of aldehydes with chiral a-amino acids, the stereogenic center of the latter is lost in the planar 1,3-dipole structure. To achieve diastereoselection in the addition to Ceo, an additional chiral element is therefore needed. An optically pure azomethine ylide was generated by reaction of (+)-2,3-0-isopropylidene-D-glyceraldehyde with... 

The Abramov reaction of 2,3-0-isopropylidene-D-glyceraldehyde and 2,4-0-ethylidene-D-ery-throse with dialkyl phosphites proceeds with very poor stereoselectivity to give the C-l di-alkoxyphosphinyl epimers in 59 41 and 53 47 ratio, respectively33. 

Mukaiyama and coworkers have pioneered many routes to the total syntheses of rare carbohydrates such as the 2-amino-2-deoxypentoses [75]. In 1982, they reported that the potassium enolate derived from the magnesium salt of the (/ )-atrolactic acid derivative 85 adds to 2,3-0-isopropylidene-D-glyceraldehyde in a highly stereoselective manner giving, after alcohol protection, imine hydrolysis and amine protection, the D-arabinopentoate derivative 86 (Scheme 13.35). Further elaboration leads to 2-acetamido-2-deoxy-D-arabinose 87. In a similar fashion, starting from (5 )-atrolactic acid, 2-acetamido-2-deoxy-D-ribose 88 was prepared [76]. 

The biologically important 2-deoxypentoses can be prepared readily by the two-carbon chain elongation of 2,3- -isopropylidene-D-glyceraldehyde following Roush s allylation method (Scheme 13.54), relying on the highly diastereoselective additions of enantiomerically pure allylboronates derived from (R,R) and (5, 5 )-tartaric acid [100]. Similarly, the 2,6-dideoxyhexose derivative 155 was obtained by Roush and Straub (Scheme 13.54) [101]. 

A synthesis of (+)-KDO has been reported by Martin and Zinke [118], which relies on the highly stereoselective addition of 2-furyllithium to 2,3-O-isopropylidene-D-glyceraldehyde R)-24. 

Condensation of 2,3-O-isopropylidene-D-glyceraldehyde-A -benzylimine 211 with 2-(tri-methylsilyloxy)furan in the presence of a Lewis acid generates a mixture of butenolides 212 that is converted into D-nZ 6>-A, A -diprotected derivative 213 in 68% yield (Scheme 13.67) [119]. Dihydroxylation of 213, followed by diol protection and lactone reduction, furnishes the 5-amino-5-deoxyheptose derivative 214. Hydrogenolysis in MeOH generates 215 and its deprotection furnishes enantiomerically pure l,5-dideoxy-l,5-imino-D-g/yc r6>-D-a//6>-heptitol 216 [120]. 

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